A man enjoying the aroma of his meal in a pan, cooking in his kitchen.

© 2024, Randy Mosher

A universal truth that keeps popping up in my search of the literature is that nothing is as simple as it seems. A sniff seems just a simple movement of air, but it’s actually way more than that: it’s a psychomotor event. 

One crucial function is to synchronize the olfactory receptor cells with the olfactory bulb and other smell-related brain regions, especially the primary olfactory processing center, the piriform cortex. This allows different regions to communicate with each other as the information about the odor flows upwards through the brain.

In smaller mammals, the brain’s 30–60 Hz gamma waves are locked to slower oscillations the same as the rate of sniffing—about 2–3 per second. We larger creatures breathe much more slowly, so our sniff frequency is slower, but still coupled to the brainwaves. This synchronization of breath and brain explains the importance of breath control in meditation and other practices. 

The system that controls sniffing is quite complex and sophisticated. It keeps track of air velocity and is able to calculate the volume of sniffed-in air. It can rapidly evaluate the hedonic quality and throttle back when the smell is unpleasant or threatening, or prolong it when pleasant. All of this happens unconsciously, within the span of a short sniff that may only last a quarter of a second. 

Good results from sniffing depends on taking in just the right amount of air at the right speed. Small ones are best—think of how a dog sniffs. Your brain knows exactly how to do this. There are no special techniques to learn. Sniffing strongly or for an extended time can actually cause your brain to habituate to certain components of a smell, changing the pattern of responses presented to your brain. This may make identification more difficult.

One short sniff is usually plenty to identify a single odor, although with complex mixtures like wine or beer, a few additional sniffs can be helpful. It may be helpful to focus on certain groups of odors you expect may be there: fruit, hops, cooked flavors, etc.


Mechanisms and functions of respiration-driven gamma oscillations in the primary olfactory cortex. 
Joaquin Gonzalez, Pablo Torterolo, Adriano BL Tort, eLife, Feb 20, 2023, 

Natural sniffing gives optimum odour perception for humans.
Laing, DG. Perception. 1983;12(2):99-117. DOI: .1068/p120099

The sniff is part of the olfactory percept.
Joel Mainland, Noam Sobel, Chemical Senses, Volume 31, Issue 2, February 2006, Pages 181–196, https://doi.org/10.1093/chemse/bjj012 

The Sniff as a Unit of Olfactory Processing. 
Adam Kepecs, Naoshige Uchida, Zachary F. Mainen, Chemical Senses, Volume 31, Issue 2, February 2006, Pages 167–179, https://doi.org/10.1093/chemse/bjj016